Joseph J. Ellis' Founding Brothers revolves around the American Revolution and the people and ideologies which accompanied the period. Most novels (both fiction and non-fiction) do not contain a typical thesis. Technically, a thesis refers to the proposition, argument, or statement an essay makes. In the case of this text, the novel itself can be considered a thesis novel (a work meant to instruct or educate on a specific subject). Founding Brothers, then, can be defined as a text which defines both the Jeffersonian and Hamiltonian interpretations of the American Revolution.
Ellis' novel is not meant to appear the preeminent factor which decides the debate between the Jeffersonians and Hamiltonians. Instead, the text illustrates the multiple and diverse personalities which came together in order to become separate themselves from England.
Therefore, there is no singular thesis in the text. Instead, the text as a whole makes a statement to the history, contradictions, people, and ideas behind the American Revolution.